Small fix to the shell.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@15879 27425a3e-05d8-49a3-a47f-9c15f0e5edd8

os/various/shell/shell.c

@@ -375,6 +375,7 @@ THD_FUNCTION(shellThread, p) {
       /* Putting a delay in order to avoid an endless loop trying to read
          an unavailable stream.*/
       osalThreadSleepMilliseconds(100);
+      continue;
 #endif
     }
     lp = parse_arguments(line, &tokp);