Refactor to use new version of OEM IPMI Handler

Using the new version of ipmi handler provide a higher level wrapper
over the same functionalities. It helps us parse the input and output to
have more control of the input/output we see.

Changes to note,
- All cmd are removed from the request data. That is automatically
  extracted now.

Tested:
Unit Test Passed.

All IPMI OEM command still works the same as before this change.

```
$ burn_my_bmc -command stage -image /tmp/test.txt -interface ipmipci
Set up ipmi flash updater with /flash/dummy
Received failure on delete: Received IPMI_CC: 255
Sending over the firmware image.
Find [0x1050 0x750]
bar0[0x94000000]
Upload to BMC 100% |Goooooooooooooooooooooooooooooooooooooooooooooooooooooooogle| Time: 00:00:00
Opening the verification file
Committing to /flash/verify to trigger service
Calling stat on /flash/verify session to check status
success
succeeded
```

Also tested gBMC Update workflow which worked fine.

Change-Id: Ib2bfeab0c2ec5aa72ede1ff457ef5f90e488053c
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/test/ipmi_unittest.cpp b/test/ipmi_unittest.cpp
index 8f27ed7..ed2f026 100644
--- a/test/ipmi_unittest.cpp
+++ b/test/ipmi_unittest.cpp
@@ -14,47 +14,37 @@
 TEST(StringInputTest, NullPointerInput)
 {
     // The method should verify it did receive a non-null input pointer.
-
-    EXPECT_STREQ("", stringFromBuffer(NULL, 5).c_str());
+    EXPECT_STREQ("", stringFromBuffer({}).c_str());
 }
 
 TEST(StringInputTest, ZeroBytesInput)
 {
     // Verify that if the input length is 0 that it'll return the empty string.
-
-    const char* request = "asdf";
-    EXPECT_STREQ("", stringFromBuffer(request, 0).c_str());
+    const std::string request = "asdf";
+    EXPECT_STREQ("", stringFromBuffer(
+                         std::vector<uint8_t>(request.begin(), request.end()))
+                         .c_str());
 }
 
 TEST(StringInputTest, NulTerminatorNotFound)
 {
     // Verify that if there isn't a nul-terminator found in an otherwise valid
     // string, it'll return the emptry string.
-
-    char request[MAX_IPMI_BUFFER];
-    std::memset(request, 'a', sizeof(request));
-    EXPECT_STREQ("", stringFromBuffer(request, sizeof(request)).c_str());
-}
-
-TEST(StringInputTest, TwoNulsFound)
-{
-    // Verify it makes you use the entire data region for the string.
-    char request[MAX_IPMI_BUFFER];
-    request[0] = 'a';
-    request[1] = 0;
-    std::memset(&request[2], 'b', sizeof(request) - 2);
-    request[MAX_IPMI_BUFFER - 1] = 0;
-
-    // This case has two strings, and the last character is a nul-terminator.
-    EXPECT_STREQ("", stringFromBuffer(request, sizeof(request)).c_str());
+    std::array<char, MAX_IPMI_BUFFER> request;
+    std::memset(request.data(), 'a', sizeof(request));
+    EXPECT_STREQ("", stringFromBuffer(
+                         std::vector<uint8_t>(request.begin(), request.end()))
+                         .c_str());
 }
 
 TEST(StringInputTest, NulTerminatorFound)
 {
     // Verify that if it's provided a valid nul-terminated string, it'll
     // return it.
-
-    const char* request = "asdf";
-    EXPECT_STREQ("asdf", stringFromBuffer(request, 5).c_str());
+    std::string request = "asdf";
+    request.push_back('\0');
+    EXPECT_STREQ("asdf", stringFromBuffer(std::vector<uint8_t>(request.begin(),
+                                                               request.end()))
+                             .c_str());
 }
 } // namespace blobs