recovery: don't use single quote

single quotes make the m4 parser think it's at the end of
a block, and generates the following compile time warning:

  external/sepolicy/recovery.te:9:WARNING 'unrecognized character' at token ''' on line 7720:

Change-Id: I2502f16f0d9ec7528ec0fc2ee65ad65635d0101b

recovery.te

@@ -59,7 +59,7 @@ recovery_only(`
 
   wakelock_use(recovery)
 
-  # This line seems suspect, as it shouldn't really need to
+  # This line seems suspect, as it should not really need to
   # set scheduling parameters for a kernel domain task.
   allow recovery kernel:process setsched;
 ')