Clean up gdb.python/ tests

Clean up gdb.python/ tests

This patch is to clean up various gdb.python/*.exp tests, such as
removing trailing ".*" from the pattern and fix one typo I find during
reading the code.

gdb/testsuite:

2014-10-15  Yao Qi  <yao@codesourcery.com>

	* gdb.python/python.exp: Remove trailing ".*".  Fix typo
	locationn.
	* gdb.python/py-symbol.exp: Remove trailing ".*" in the
	pattern.
	* gdb.python/py-symtab.exp: Likewise.