UML: normalize global variables exported by vmlinux.lds

Normalize global variables exported by vmlinux.lds to conform usage
guidelines from include/asm-generic/sections.h.

1) Use _text to mark the start of the kernel image including the head
text, and _stext to mark the start of the .text section.
2) Export mandatory global variables __bss_stop.
3) Adjust __init_begin and __init_end to avoid acrossing .text and
   .data sections.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
index ff65fb4..6899195 100644
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -20,13 +20,12 @@
   . = START + SIZEOF_HEADERS;
 
   _text = .;
-  _stext = .;
-  __init_begin = .;
   INIT_TEXT_SECTION(0)
   . = ALIGN(PAGE_SIZE);
 
   .text      :
   {
+    _stext = .;
     TEXT_TEXT
     SCHED_TEXT
     LOCK_TEXT
@@ -62,7 +61,10 @@
 
   #include <asm/common.lds.S>
 
+  __init_begin = .;
   init.data : { INIT_DATA }
+  __init_end = .;
+
   .data    :
   {
     INIT_TASK_DATA(KERNEL_STACK_SIZE)
@@ -97,6 +99,7 @@
   PROVIDE(_bss_start = .);
   SBSS(0)
   BSS(0)
+   __bss_stop = .;
   _end = .;
   PROVIDE (end = .);