Fix memory ios facts (#21696)

In order to populate the total and free mem of an IOS device, we run
the 'show memory statistics' command.
The output shows something similar to:

                Head    Total(b)     Used(b)     Free(b)   Lowest(b)  Largest(b)
Processor    BEAE880   335215488    64044364   271171124   268918092   268463852
      I/O    8DAE880    51380224    41880736     9499488     9461552     9352252

We need to just parse the line containing 'Processor' and get the first and third
number for total and free mem, instaed for first and second as the code wrongly
does.

lib/ansible/modules/network/ios/ios_facts.py

@@ -222,10 +222,12 @@ class Hardware(FactsBase):
 
         data = self.responses[1]
         if data:
-            match = re.findall(r'\s(\d+)\s', data)
+            processor_line = [l for l in data.splitlines()
+                              if 'Processor' in l].pop()
+            match = re.findall(r'\s(\d+)\s', processor_line)
             if match:
                 self.facts['memtotal_mb'] = int(match[0]) / 1024
-                self.facts['memfree_mb'] = int(match[1]) / 1024
+                self.facts['memfree_mb'] = int(match[3]) / 1024
 
     def parse_filesystems(self, data):
         return re.findall(r'^Directory of (\S+)/', data, re.M)