Correct name of harness file and reference to it in Makefile

This ensures that genenerated SMT filenames are unique
for all C functions.

Signed-off-by: Rod Chapman <rodchap@amazon.com>

Author: rod-chapman

proofs/cbmc/poly_getnoise_eta1_4x_native/Makefile

@@ -4,7 +4,7 @@
 include ../Makefile_params.common
 
 HARNESS_ENTRY = harness
-HARNESS_FILE = poly_getnoise_eta1_4x_harness
+HARNESS_FILE = poly_getnoise_eta1_4x_native_harness
 
 # This should be a unique identifier for this proof, and will appear on the
 # Litani dashboard. It can be human-readable and contain spaces if you wish.