OvmfPkg: Update code to be more C11 compliant by using __func__

__FUNCTION__ is a pre-standard extension that gcc and Visual C++ among
others support, while __func__ was standardized in C99.

Since it's more standard, replace __FUNCTION__ with __func__ throughout
OvmfPkg.

Signed-off-by: Rebecca Cran <rebecca@bsdio.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>

OvmfPkg/Library/PlatformBootManagerLibBhyve/BdsPlatform.c

@@ -273,7 +273,7 @@ RemoveStaleFvFileOptions (
     DEBUG ((
       EFI_ERROR (Status) ? DEBUG_WARN : DEBUG_VERBOSE,
       "%a: removing stale Boot#%04x %s: %r\n",
-      __FUNCTION__,
+      __func__,
       (UINT32)BootOptions[Index].OptionNumber,
       DevicePathString == NULL ? L"<unavailable>" : DevicePathString,
       Status
@@ -586,7 +586,7 @@ ConnectVirtioPciRng (
   return EFI_SUCCESS;
 
 Error:
-  DEBUG ((DEBUG_ERROR, "%a: %r\n", __FUNCTION__, Status));
+  DEBUG ((DEBUG_ERROR, "%a: %r\n", __func__, Status));
   return Status;
 }
 
@@ -1156,7 +1156,7 @@ SetPciIntLine (
       DEBUG ((
         DEBUG_ERROR,
         "%a: PCI host bridge (00:00.0) should have no interrupts!\n",
-        __FUNCTION__
+        __func__
         ));
       ASSERT (FALSE);
     }
@@ -1213,7 +1213,7 @@ SetPciIntLine (
       DEBUG ((
         DEBUG_VERBOSE,
         "%a: [%02x:%02x.%x] %s -> 0x%02x\n",
-        __FUNCTION__,
+        __func__,
         (UINT32)Bus,
         (UINT32)Device,
         (UINT32)Function,
@@ -1283,7 +1283,7 @@ PciAcpiInitialization (
       DEBUG ((
         DEBUG_ERROR,
         "%a: Unknown Host Bridge Device ID: 0x%04x\n",
-        __FUNCTION__,
+        __func__,
         mHostBridgeDevId
         ));
       ASSERT (FALSE);