libmount: don't return root if path contains // or ending /

If the path fx. is /foo/bar/ the initial stripoff will replace the last slash
with \0 and return a pointer to that exact \0 character. The same thing will
happen if the path contains // somewhere.

Signed-off-by: Søren Holm <sgh@sgh.dk>

libmount/src/tab.c

@@ -864,7 +864,7 @@ struct libmnt_fs *mnt_table_find_mountpoint(struct libmnt_table *tb,
 		}
 
 		p = stripoff_last_component(mnt);
-		if (!p || !*p)
+		if (!p)
 			break;
 	} while (mnt && *(mnt + 1) != '\0');