parisc: Consider stack randomization for mmap base only when necessary

Do not offset mmap base address because of stack randomization if
current task does not want randomization.

Signed-off-by: Alexandre Ghiti <[e-mail]>
Signed-off-by: Helge Deller <[e-mail]>

arch/parisc/kernel/sys_parisc.c

···
 		stack_base = STACK_SIZE_MAX;
 
 	/* Add space for stack randomization. */
-	stack_base += (STACK_RND_MASK << PAGE_SHIFT);
+	if (current->flags & PF_RANDOMIZE)
+		stack_base += (STACK_RND_MASK << PAGE_SHIFT);
 
 	return PAGE_ALIGN(STACK_TOP - stack_base);
 }