util/cbfstool: Fix typos

Change-Id: I6967a106ce1286d633ddeeb041f582e65f9ea78c
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/28208
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Martin Roth <martinroth@google.com>

util/cbfstool/common.c

@@ -29,7 +29,7 @@
 /* Utilities */
 int verbose = 0;
 
-/* Small, OS/libc independent runtime check for endianess */
+/* Small, OS/libc independent runtime check for endianness */
 int is_big_endian(void)
 {
 	static const uint32_t inttest = 0x12345678;