fix string

Author: simonpintarelli

ci/tests.bats

@@ -66,7 +66,7 @@ function teardown() {
     # only one @<offset> is allowed
     run squashfs-mount ${SQFSDIR}/tools-offset.sqfs@2@2:/user-tools -- cat /user-tools/tools/fileB.txt
     assert_failure
-    assert_line  --regexp ".*invalid format:.*"
+    assert_line  --regexp ".*invalid format: .*"
 }
 
 @test "mount_images" {

squashfs-mount.c

@@ -208,7 +208,7 @@ static mount_entry_t *parse_mount_entries(const char **argv, int argc) {
       }
       // expect file_and_offset only contains one `@`
       if (strtok(NULL, "@")) {
-        errx(EXIT_FAILURE, "invalid format %s", argv[i]);
+        errx(EXIT_FAILURE, "invalid format: %s", argv[i]);
       }
     }