Do not add empty paths to output file

This commit fixes a bug in the script where an undefined (blank)
path would get added to the output inventory file in case the
path for a given FRU is not found in both the MRW and the
default path map.

Having an empty path would result in a bad inventory environment
file that would cause the openpower vpd parser service that relies
on this file to fail at runtime.

Tested:
I ran the script manually against the witherspoon MRW and the
openpower layout YAML and verified that the generated inventory
file was good.

Change-Id: I6443208bd3e9e7705da40c30799f007a386b3612
Signed-off-by: Santosh Puranik <santosh.puranik@in.ibm.com>
diff --git a/gen_openpower_fru.pl b/gen_openpower_fru.pl
index 066c949..3eefc3e 100755
--- a/gen_openpower_fru.pl
+++ b/gen_openpower_fru.pl
@@ -64,9 +64,12 @@
 
 for my $type (keys %targetHash)
 {
-    # One or more targets wasn't present in the inventory
-    push @targetTypes, $type;
-    push @paths, $defaultPaths{$type};
+    if(defined $defaultPaths{$type})
+    {
+        # One or more targets wasn't present in the inventory
+        push @targetTypes, $type;
+        push @paths, $defaultPaths{$type};
+    }
 }
 
 open(my $fh, '>', $outFile) or die "Could not open file '$outFile' $!";