sparc64: Do not retain old VM_SPARC_ADI flag when protection changes on page

sparc64: Do not retain old VM_SPARC_ADI flag when protection changes on page

When protection on a memory page is changed with mprotect(), old
arch-specific VM flags on the page are retained. This patch clears
old VM_SPARC_ADI flag when protection is changed since mprotect() is
potentially being invoked to disable ADI on the page. This code will
add VM_SPARC_ADI flag back if the new protection includes it.

Orabug: 25641371

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>