[arch][arm] update stackusage script for python3
The old regexp needed to be updated to remove a warning.
diff --git a/arch/arm/stackusage b/arch/arm/stackusage
index d675b7e..de1adf8 100755
--- a/arch/arm/stackusage
+++ b/arch/arm/stackusage
@@ -5,9 +5,9 @@
hexrule = re.compile("([0-9a-fA-F]+)")
hex2byterule = re.compile("([0-9a-fA-F]{4})")
-hexcolonrule = re.compile("([0-9a-fA-F]+)\:")
-symbolrule = re.compile("<([\._a-zA-Z]+[\._0-9a-zA-Z]*)>:")
-insrule = re.compile("([a-zA-Z][\.a-zA-Z]*)")
+hexcolonrule = re.compile("([0-9a-fA-F]+):")
+symbolrule = re.compile("<([._a-zA-Z]+[._0-9a-zA-Z]*)>:")
+insrule = re.compile("([a-zA-Z][.a-zA-Z]*)")
currsymbol = ""
curraddress = 0