Fix report_coverage (#3781)

Summary: Pull Request resolved: #3781

Test Plan:
Example output for linux: https://productionresultssa4.blob.core.windows.net/actions-results/93032995-b46e-4f8d-b1be-252f73034a4e/workflow-job-run-5492d855-e93e-5189-8cb4-88a0b1a3132f/logs/job/job-logs.txt?rsct=text%2Fplain&se=2024-05-30T21%3A11%3A50Z&sig=OIOn1jyO3DFXpDA%2FTb%2Fc27PEnUkT0D9JgIzVZmXWsxE%3D&ske=2024-05-31T08%3A04%3A04Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2024-05-30T20%3A04%3A04Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2023-11-03&sp=r&spr=https&sr=b&st=2024-05-30T21%3A01%3A45Z&sv=2023-11-03
Example output for macos: https://productionresultssa4.blob.core.windows.net/actions-results/93032995-b46e-4f8d-b1be-252f73034a4e/workflow-job-run-00b9f9ca-16b3-535c-a3c3-70113f2f2d24/logs/job/job-logs.txt?rsct=text%2Fplain&se=2024-05-30T21%3A11%3A20Z&sig=RhmOz09HvOdrU1UKQCsnEoL3G8Cu%2BwrzmK4N4MTpsu0%3D&ske=2024-05-31T08%3A04%3A18Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2024-05-30T20%3A04%3A18Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2023-11-03&sp=r&spr=https&sr=b&st=2024-05-30T21%3A01%3A15Z&sv=2023-11-03

Reviewed By: huydhn

Differential Revision: D57980848

Pulled By: kirklandsign

fbshipit-source-id: 68f79702ba531b7f7df999de4ca154e32f67dd83

Author: kirklandsign

test/run_oss_cpp_tests.sh

@@ -74,8 +74,8 @@ build_and_run_test() {
 }
 
 report_coverage() {
-  "${LLVM_PROFDATA}" merge -sparse cmake-out/*.profraw -o cmake-out/merged.profdata
-  "${LLVM_COV}" report -instr-profile=cmake-out/merged.profdata $TEST_BINARY_LIST
+  ${LLVM_PROFDATA} merge -sparse cmake-out/*.profraw -o cmake-out/merged.profdata
+  ${LLVM_COV} report -instr-profile=cmake-out/merged.profdata $TEST_BINARY_LIST
 }
 
 probe_tests() {