parisc: Fix map_pages() to not overwrite existing pte entries

commit 3c229b3f upstream.

Fix a long-existing small nasty bug in the map_pages() implementation which
leads to overwriting already written pte entries with zero, *if* map_pages() is
called a second time with an end address which isn't aligned on a pmd boundry.
This happens for example if we want to remap only the text segment read/write
in order to run alternative patching on the code. Exiting the loop when we
reach the end address fixes this.

Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/parisc/mm/init.c

@@ -494,12 +494,8 @@ static void __init map_pages(unsigned long start_vaddr,
 						pte = pte_mkhuge(pte);
 				}
 
-				if (address >= end_paddr) {
-					if (force)
-						break;
-					else
-						pte_val(pte) = 0;
-				}
+				if (address >= end_paddr)
+					break;
 
 				set_pte(pg_table, pte);