Bitmap file data is read looping through the lines in the input file. If
there is extra data after the bitmap, these lines will be processed and
if this data represents another bitmap it will replace the one read
before causing the memory allocated for bits to leak.

This changes the code to stop processing the file once a bitmap was
read.
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan-de-oliveira@nokia.com>
Reviewed-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Backported-to-NX-by: Ulrich Sibiller <uli42@gmx.de>