[IA64] sys_mmap doesn't follow posix.1 when parameter len=0
[IA64] sys_mmap doesn't follow posix.1 when parameter len=0

In IA64 kernel, sys_mmap calls do_mmap2 and do_mmap2 returns addr if
len=0, which means the mmap sys call succeeds.

Posix.1 says:
The mmap() function shall fail if:
[EINVAL] The value of len is zero. 

Here is a patch to fix it.

Signed-off-by: Zhang Yanmin <5aa8ede52005e38a48fccf8ed843c06a1c45986c@intel.com>
Acked-by: David Mosberger <d1d8db213f7904be6fe86c5e953cc98b1d326545@hpl.hp.com>
Signed-off-by: Tony Luck <e7984595ec0368ff920a7b3521dc7093683f6f26@intel.com>

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