arm64: stacktrace: delete PCS comment

The comment at the top of stacktrace.c isn't all that helpful, as it's
not associated with the code which inspects the frame record, and the
code example isn't representative of common code generation today.

Delete it.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <[email protected]>
Cc: Madhavan T. Venkataraman <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Will Deacon <[email protected]>
Reviewed-by: Madhavan T. Venkataraman <[email protected]>
Reviewed-by: Mark Brown <[email protected]>
Reviewed-by: Kalesh Singh <[email protected]> for the series.
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

arch/arm64/kernel/stacktrace.c

@@ -18,21 +18,6 @@
 #include <asm/stack_pointer.h>
 #include <asm/stacktrace.h>
 
-/*
- * AArch64 PCS assigns the frame pointer to x29.
- *
- * A simple function prologue looks like this:
- * 	sub	sp, sp, #0x10
- *   	stp	x29, x30, [sp]
- *	mov	x29, sp
- *
- * A simple function epilogue looks like this:
- *	mov	sp, x29
- *	ldp	x29, x30, [sp]
- *	add	sp, sp, #0x10
- */
-
-
 static notrace void start_backtrace(struct stackframe *frame, unsigned long fp,
 				    unsigned long pc)
 {