Update run-make PGO test to new commandline syntax.

Author: michaelwoerister

src/test/run-make-fulldeps/pgo-gen-no-imp-symbols/Makefile

@@ -2,7 +2,7 @@
 
 all:
 ifeq ($(PROFILER_SUPPORT),1)
-	$(RUSTC) -O -Ccodegen-units=1 -Z pgo-gen="$(TMPDIR)/test.profraw" --emit=llvm-ir test.rs
+	$(RUSTC) -O -Ccodegen-units=1 -Z pgo-gen="$(TMPDIR)" --emit=llvm-ir test.rs
 	# We expect symbols starting with "__llvm_profile_".
 	$(CGREP) "__llvm_profile_" < $(TMPDIR)/test.ll
 	# We do NOT expect the "__imp_" version of these symbols.