DESC
remap_file_pages protection support: adapt to uml peculiarities
EDESC
From: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>

Uml is particular in respect with other architectures (and possibly this is to
fix) in the fact that our arch fault handler handles indifferently both TLB
and page faults. In particular, we may get to call handle_mm_fault() when the
PTE is already correct, but simply it's not flushed.

And rfp-fault-sigsegv-2 breaks this, because when getting a fault on a
pte_present PTE and non-uniform VMA, it assumes the fault is due to a
protection fault, and signals the caller a SIGSEGV must be sent.

This isn't the final fix for UML, that's the next one.
