bugfix: process: can be only crc

The read command, if returning 0 bytes of data, does return the CRC.

Tested: Verified via a client implementation that it now behaves as
expected on returning 0 bytes from a read (returns only the CRC).
Change-Id: I84200c0fbe8400cc9234b55991fee750cb84faa2
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/process.cpp b/process.cpp
index 683bf77..a73f70e 100644
--- a/process.cpp
+++ b/process.cpp
@@ -128,8 +128,10 @@
         return result;
     }
 
-    /* The response, if it has one byte, has three, to include the crc16. */
-    if (replyLength < (sizeof(uint16_t) + 1))
+    /* Read can return 0 bytes, and just a CRC, otherwise you need a CRC and 1
+     * byte, therefore the limit is 2 bytes.
+     */
+    if (replyLength < (sizeof(uint16_t)))
     {
         return IPMI_CC_UNSPECIFIED_ERROR;
     }