config: arm: fix os_flags
Fix the makeArmSystem routine to reflect recent changes that support kernel
commandline option when running android. Without this fix, trying to run
android encounters a 'reference before assignment' error.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
diff --git a/configs/common/FSConfig.py b/configs/common/FSConfig.py
index 50c5bc4..88de3b8 100644
--- a/configs/common/FSConfig.py
+++ b/configs/common/FSConfig.py
@@ -286,7 +286,7 @@
         self.flags_addr = self.realview.realview_io.pio_addr + 0x30
 
         if mdesc.disk().lower().count('android'):
-            boot_flags += " init=/init "
+            cmdline += " init=/init "
         self.boot_osflags = fillInCmdline(mdesc, cmdline)
     self.realview.attachOnChipIO(self.membus, self.bridge)
     self.realview.attachIO(self.iobus)