main: Fix parsing of plymouth.debug=stream: argument.

It did not terminate at space so the log file to use was not
properly defined and any additional kernel command line args were
added to the end of the file name.

src/main.c

@@ -1797,6 +1797,12 @@ check_verbosity (state_t *state)
 
       if (stream != NULL)
         {
+          char *end;
+
+          stream = strdup (stream);
+          end = stream + strcspn (stream, " \n");
+          *end = '\0';
+
           ply_trace ("streaming debug output to %s instead of screen", stream);
           fd = open (stream, O_RDWR | O_NOCTTY | O_CREAT, 0600);
 
@@ -1808,6 +1814,7 @@ check_verbosity (state_t *state)
             {
               ply_logger_set_output_fd (ply_logger_get_error_default (), fd);
             }
+          free (stream);
         }
     }
   else