python3 fixes

Tools/px_generate_params.py

@@ -3,8 +3,8 @@ import xml.etree.ElementTree as ET
 import os
 
 if len(os.sys.argv) != 2:
-	print "Error in %s" % os.sys.argv[0]
-	print "Usage: %s <parameters.xml>"
+	print("Error in %s" % os.sys.argv[0])
+	print("Usage: %s <parameters.xml>" % os.sys.argv[0])
 	raise SystemExit
 
 fp_header = open("px4_parameters.h", "w")

Tools/px_romfs_pruner.py

@@ -77,7 +77,7 @@ def main():
 
                         # overwrite old scratch file
                         with open(file_path, "wb") as f:
-                                f.write(pruned_content)
+                                f.write(pruned_content.encode("ascii", errors='strict'))
 
 
 if __name__ == '__main__':