udev: add missing new-line in udevadm error

fprintf() does not add new-lines automatically like log_*() does. Add the
missing \n specified so "udevadm" invoked without arguments adds a newline
to:
    udevadm: missing or unknown command

1 files changed, 1 insertions, 1 deletions

diff --git a/src/udev/udevadm.c b/src/udev/udevadm.c
index 2c11550467..df546dd823 100644
--- a/src/udev/udevadm.c
+++ b/src/udev/udevadm.c
@@ -134,7 +134,7 @@ int main(int argc, char *argv[]) {
                                 goto out;
                         }
 
-        fprintf(stderr, "%s: missing or unknown command", program_invocation_short_name);
+        fprintf(stderr, "%s: missing or unknown command\n", program_invocation_short_name);
         rc = 2;
 out:
         label_finish();