ARC: mm: pte flags comsetic cleanups, comments

No semantical changes

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/mm/tlbex.S

@@ -365,7 +365,7 @@ ENTRY(EV_TLBMissD)
 	lr      r3, [ecr]
 	or      r0, r0, _PAGE_ACCESSED        ; Accessed bit always
 	btst_s  r3,  ECR_C_BIT_DTLB_ST_MISS   ; See if it was a Write Access ?
-	or.nz   r0, r0, _PAGE_MODIFIED        ; if Write, set Dirty bit as well
+	or.nz   r0, r0, _PAGE_DIRTY           ; if Write, set Dirty bit as well
 	st_s    r0, [r1]                      ; Write back PTE
 
 	CONV_PTE_TO_TLB