dsp: bios_table: Tidy up pldm_bios_table_pad_checksum_size()

There was no need for the intermediate variable, and the comment isn't
informative enough for it to remain.

Change-Id: I82881bb49703e08c4797cbc6e70aaeb889603ca3
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/src/dsp/bios_table.c b/src/dsp/bios_table.c
index f7c1206..8552106 100644
--- a/src/dsp/bios_table.c
+++ b/src/dsp/bios_table.c
@@ -910,9 +910,7 @@
 LIBPLDM_ABI_STABLE
 size_t pldm_bios_table_pad_checksum_size(size_t size_without_pad)
 {
-	size_t size = pad_size_get(size_without_pad) +
-		      sizeof(uint32_t) /*sizeof(checksum)*/;
-	return size;
+	return pad_size_get(size_without_pad) + sizeof(uint32_t);
 }
 
 LIBPLDM_ABI_STABLE