[ARM] 3853/1: Fix flush_ptrace_access() thinko for nonaliasing VIPT cache case

Fix thinko in the flush_ptrace_access() "if (expr)" for the ARM
VIPT non-aliasing cache case.  We only need to flush cache when
VM_EXEC is set in vma->vm_flags but "if (expr) always evaluates
to true on UP systems for the ARM VIPT non-aliasing cache case.

Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>