openrisc: entry: Whitespace and comment cleanups

Cleanups to whitespace and add some comments. Reading through the delay
slot logic I noticed some things:
 - Delay slot instructions were not indented
 - Some comments are not lined up
 - Use tabs and spaces consistent with other code

No functional change
Signed-off-by: Stafford Horne <shorne@gmail.com>

arch/openrisc/kernel/entry.S

@@ -244,23 +244,21 @@ EXCEPTION_ENTRY(_data_page_fault_handler)
 	l.bf    8f
 	l.sfeqi r6,0x12                    // l.jalr
 	l.bf    8f
-
 	 l.nop
 
 	l.j     9f
 	 l.nop
-8:
 
+8: // offending insn is in delay slot
 	l.lwz   r6,PT_PC(r3)               // address of an offending insn
 	l.addi  r6,r6,4
 	l.lwz   r6,0(r6)                   // instruction that caused pf
 	l.srli  r6,r6,26                   // get opcode
-9:
+9: // offending instruction opcode loaded in r6
 
 #else
 
 	l.mfspr r6,r0,SPR_SR               // SR
-//	l.lwz	r6,PT_SR(r3)		   // ESR
 	l.andi  r6,r6,SPR_SR_DSX           // check for delay slot exception
 	l.sfeqi r6,0x1                     // exception happened in delay slot
 	l.bnf   7f