Ubuntu 22.04 integration: Cppcheck

Suppress a false positive found by new Cppcheck version.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #14148

lib/libshare/nfs.c

@@ -91,6 +91,7 @@ nfs_init_tmpfile(const char *prefix, const char *mdir, struct tmpfile *tmpf)
 	    mkdir(mdir, 0755) < 0 &&
 	    errno != EEXIST) {
 		fprintf(stderr, "failed to create %s: %s\n",
+		// cppcheck-suppress uninitvar
 		    mdir, strerror(errno));
 		return (B_FALSE);
 	}