util/cbfstool: Fix typos

Found by: util/lint/checkpatch.pl --types TYPO_SPELLING --fix-inplace
--strict --terse -f util/cbfstool/*.c

Change-Id: I13a27407bf2bad4b9fadcec8cdbd5889068f13cf
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38633
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/cbfstool/rmodule.c

@@ -223,7 +223,7 @@ static int find_program_segment(struct rmod_context *ctx)
 	}
 
 	if (nsegments != 1) {
-		ERROR("Unexepcted number of loadable segments: %d.\n",
+		ERROR("Unexpected number of loadable segments: %d.\n",
 		      nsegments);
 		return -1;
 	}