RDMA/efa: Remove MAYEXEC flag check from mmap flow

RDMA/efa: Remove MAYEXEC flag check from mmap flow

MAYEXEC test was mistakenly added, remove it. Checking MAYEXEC in the
driver prevents it from working with userspace that uses things like EXEC
STACK. (ie some Fortran and other runtimes)

Fixes: 0c1a5f4cd0b6 ("RDMA/efa: Add EFA verbs implementation")
Reported-by: Jason Gunthorpe <jgg@ziepe.ca>
Reviewed-by: Firas JahJah <firasj@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>