forensics/mxvmem: strings in regexes may need the 'raw' modifier

Without r'...', one will get a warning about \d and so on.
Future versions will treat this as an error.

forensics/mxvmem

@@ -183,7 +183,7 @@ class ProcStreamParser():
   '''
   def __init__(self,procfshandler):
     self.pfh      = procfshandler
-    self.pidrex   = re.compile('/proc/(\d+)/(\S+)\s+(.*)') # :xxx: hardcoded '/proc'
+    self.pidrex   = re.compile(r'/proc/(\d+)/(\S+)\s+(.*)') # :xxx: hardcoded '/proc'
 
   def parse(self, line):
     m = self.pidrex.match(line)