[MIPS] MIPSsim: Fix booting from NFS root

MIPSsim probably doesn't have any sort of environment, but writing
a zero in it kills even the compiled in command line. This prevents
booting via NFS root.
Signed-Off-By: NThiemo Seufer <ths@networkno.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/mipssim/sim_cmdline.c

@@ -28,8 +28,5 @@ char * __init prom_getcmdline(void)
 
 void  __init prom_init_cmdline(void)
 {
-	char *cp;
-	cp = arcs_cmdline;
-	/* Get boot line from environment? */
-	*cp = '\0';
+	/* XXX: Get boot line from environment? */
 }