[compiler-rt][memprof] Disambiguate checks for __tls_get_addr in output

TestCases/stress_dtls.c was failing when we ran memprof tests for the first
time. The test checks that __tls_get_addr is not in the output for the last
run when it is possible for the interceptor __interceptor___tls_get_addr to
be in the output from stack dumps. The test actually intends to check that
the various __tls_get_addr reports don't get emitted when intercept_tls_get_addr=0.
This updates the test to also check for the following `:` and preceding `==`
which should ignore the __interceptor___tls_get_addr interceptor.

Differential Revision: https://reviews.llvm.org/D111192