Update srs_core_performance.hpp (#3160)
Update srs_core_performance.hpp (#3160)

In included file: main file cannot be included recursively when building a preamble
    clang(pp_including_mainfile_in_preamble)
    srs_core.hpp(43, 10): Error occurred here
ossrs/srs,winlinvip/srs,winlinvip/srs,ossrs/srs,ossrs/srs,ossrs/srs,winlinvip/srs,winlinvip/srs,winlinvip/srs,ossrs/srs,ossrs/srs,winlinvip/srs