svf: flush the queue before reallocing memory

svf: flush the queue before reallocing memory

During reallocation a new memory region might be allocated and the old
one freed. If jtag queue is holding a pointer to the old memory, it will
segfault during the execution. Avoid this by flushing the queue before a
reallocation attempt is made.

This should fix ticket #102.

Change-Id: I737fc3f1ebf6d76413a475beb8bf20184fe0233f
Reported-by: Alex Forencich <aforencich@users.sf.net>
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/2899
Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>