Prevent commitcheck.sh from running twice

A stray semicolon was causing commitcheck.sh
to run twice when running make checkstyle.
Updated regexes for matching tagged lines.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Closes #5952

Makefile.am

@@ -55,7 +55,7 @@ shellcheck:
 		shellcheck --exclude=SC1090 --format gcc scripts/paxcheck.sh \
 			scripts/zloop.sh \
 			scripts/zfs-tests.sh \
-			scripts/zfs.sh; \
+			scripts/zfs.sh \
 			scripts/commitcheck.sh; \
 		(find cmd/zed/zed.d/*.sh -type f) | \
 		 grep -v 'zfs-script-config' | \