staging: goldfish: Introduce the use of managed interfaces

This patch introduces the use of managed interfaces like devm_kzalloc,
devm_ioremap, dmam_alloc_coherent, devm_request_irq and does away with
the calls to functions to free the allocated memory in the probe and
remove functions. Also, the labels are removed in the probe function.

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>