fix build failure

Seeing the following in Yocto:

```
09:57:11 | ../git/src/oemcommands.cpp: In function 'ipmi::RspType<std::vector<unsigned char, std::allocator<unsigned char> > > ipmi::ipmiOemQGetDimmInfo(Context::ptr, uint8_t, uint8_t, uint8_t, uint8_t, uint8_t)':
09:57:11 | ../git/src/oemcommands.cpp:1683:31: error: 'findHost' is not a member of 'ipmi::boot'; did you mean 'findHost'?
09:57:11 |  1683 |     auto hostId = ipmi::boot::findHost(ctx->hostIdx);
```

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ib2379bd5248296f7554fc8ea77d19034dbdfee4c
diff --git a/src/oemcommands.cpp b/src/oemcommands.cpp
index 7482e1c..30d183c 100644
--- a/src/oemcommands.cpp
+++ b/src/oemcommands.cpp
@@ -1585,7 +1585,7 @@
     uint8_t len = request.size();
     std::string dimmType;
     readDimmType(dimmType, dimmIndex);
-    auto hostId = ipmi::boot::findHost(ctx->hostIdx);
+    auto hostId = findHost(ctx->hostIdx);
     if (!hostId)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(
@@ -1680,7 +1680,7 @@
     std::string str;
     std::string dimmType;
     readDimmType(dimmType, dimmIndex);
-    auto hostId = ipmi::boot::findHost(ctx->hostIdx);
+    auto hostId = findHost(ctx->hostIdx);
     if (!hostId)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(