[MIPS] IRIX: Handle do_brk() error return correctly.
[MIPS] IRIX: Handle do_brk() error return correctly.

do_brk's return value was stored in an unsigned long variable before being
tested for less than zero making the test always fail.  Also do_brk's
called irix_map_prda_page wasn't forwarding do_brk() success.

Bug checking the return value of do_brk() and initial fix for it found
by Roel Kluin <12o3l@tiscali.nl>.

Signed-off-by: Ralf Baechle <92f48d309cda194c8eda36aa8f9ae28c488fa208@linux-mips.org>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs