scripts: dtrace2systemtap: Fix argument name extraction regex to avoid '*' in names

When commit d249170bf6 modified the arguments of
'virNetTLSContextNew' which has a systemtap probe defined the
'dtrace2systemtap' script was no longer to correctly generate the
definitions for it.

First problem which stemmed from mis-detecting the string array
argumment as string, which would use 'user_string' to extract it was
fixed in cb33103c4a.

After that the generated probe is still not correct because it doesn't
strip all the '*' from pointers and thus for double pointers it
generates the following invalid definition:

  probe libvirt.rpc.tls_context_new = process("/usr/lib64/libvirt.so").mark("rpc_tls_context_new") {
    ctxt = $arg1;
    cacert = user_string($arg2);
    cacrl = user_string($arg3);
    *cert = $arg4;
    *keys = $arg5;
    sanityCheckCert = $arg6;
    requireValidCert = $arg7;
    isServer = $arg8;
  }

Leading to the following failure:

  # stap -ve 'probe oneshot {exit()}'
  parse error: expected literal string or number
          saw: operator '*' at /usr/share/systemtap/tapset/libvirt_probes-64.stp:204:3
       source:   *cert = $arg4;
                 ^
  1 parse error.

To address the issue the regex extracting the arguments needs to
optionally match any number of '*' instead of just one.

Resolves: https://issues.redhat.com/browse/RHEL-153832
Fixes: cb33103c4a
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>

scripts/dtrace2systemtap.py

@@ -127,7 +127,7 @@ for file in filelist:
             if re.match(r'''.*char\s\*[^\*].*''', arg) is not None:
                 isstr = True
 
-            m = re.search(r'''^.*\s\*?(\S+)$''', arg)
+            m = re.search(r'''^.*\s\**(\S+)$''', arg)
             if m is not None:
                 arg = m.group(1)
             else: