Need reviewer: 7034700: simple fix

[Kumar Srinivasan]

Hi,

This fixes a build issue in non-product builds, with the fix for 7033954.
During the pack200 build the wrong mapfile is picked up due to the
idiosyncrasy of the makefile. Thus the fix is simply and explicitly 
instructing
Mapfile-vers.gmk  not to use a mapfile for a non-product build.

http://cr.openjdk.java.net/~ksrini/7034700/webrev.0/

Thanks
Kumar

PS:
the previous change which activates mapfile checking,  for reference :
  http://cr.openjdk.java.net/~ksrini/7033954/webrev.0/make/com/sun/java/pack/Makefile.udiff.html