scripts: decode_stacktrace: fix ARM architecture decoding

Fix the stack decoder for the ARM architecture.
An ARM stack is designed as :

[   81.547704] [<c023eb04>] (bucket_find_contain) from [<c023ec88>] (check_sync+0x40/0x4f8)
[   81.559668] [<c023ec88>] (check_sync) from [<c023f8c4>] (debug_dma_sync_sg_for_cpu+0x128/0x194)
[   81.571583] [<c023f8c4>] (debug_dma_sync_sg_for_cpu) from [<c0327dec>] (__videobuf_s

The current script doesn't expect the symbols to be bound by
parenthesis, and triggers the following errors :

  awk: cmd. line:1: error: Unmatched ( or \(: / (check_sync$/
  [   81.547704] (bucket_find_contain) from (check_sync+0x40/0x4f8)

Fix it by chopping starting and ending parenthesis from the each symbol
name.

As a side note, this probably comes from the function
dump_backtrace_entry(), which is implemented differently for each
architecture.  That makes a single decoding script a bit a challenge.
Signed-off-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

scripts/decode_stacktrace.sh

@@ -14,11 +14,14 @@ declare -A cache
 
 parse_symbol() {
 	# The structure of symbol at this point is:
-	#   [name]+[offset]/[total length]
+	#   ([name]+[offset]/[total length])
 	#
 	# For example:
 	#   do_basic_setup+0x9c/0xbf
 
+	# Remove the englobing parenthesis
+	symbol=${symbol#\(}
+	symbol=${symbol%\)}
 
 	# Strip the symbol name so that we could look it up
 	local name=${symbol%+*}