Remove obsolete target covtest

This target dates back from before basic-build-test.sh existed. Refer to
that script instead.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3a870a7..6bf9fae 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -304,13 +304,13 @@
     # additional convenience targets for Unix only
     if(UNIX)
 
-        ADD_CUSTOM_TARGET(covtest
-            COMMAND make test
-            COMMAND programs/test/selftest
-            COMMAND tests/compat.sh
-            COMMAND tests/ssl-opt.sh
-        )
-
+        # For coverage testing:
+        # 1. Build with:
+        #         cmake -D CMAKE_BUILD_TYPE=Coverage /path/to/source && make
+        # 2. Run the relevant tests for the part of the code you're interested in.
+        #    For the reference coverage measurement, see
+        #    tests/scripts/basic-build-test.sh
+        # 3. Run scripts/lcov.sh to generate an HTML report.
         ADD_CUSTOM_TARGET(lcov
             COMMAND scripts/lcov.sh
         )
diff --git a/Makefile b/Makefile
index af44305..2f1be65 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@
 
 .SILENT:
 
-.PHONY: all no_test programs lib tests install uninstall clean test check covtest lcov apidoc apidoc_clean
+.PHONY: all no_test programs lib tests install uninstall clean test check lcov apidoc apidoc_clean
 
 all: programs tests
 	$(MAKE) post_build
@@ -136,15 +136,13 @@
 test: check
 
 ifndef WINDOWS
-# Note: for coverage testing, build with:
-#     make CFLAGS='--coverage -g3 -O0' LDFLAGS='--coverage'
-# For the reference coverage measurement, see tests/scripts/basic-build-test.sh
-covtest:
-	$(MAKE) check
-	programs/test/selftest
-	tests/compat.sh
-	tests/ssl-opt.sh
-
+# For coverage testing:
+# 1. Build with:
+#         make CFLAGS='--coverage -g3 -O0' LDFLAGS='--coverage'
+# 2. Run the relevant tests for the part of the code you're interested in.
+#    For the reference coverage measurement, see
+#    tests/scripts/basic-build-test.sh
+# 3. Run scripts/lcov.sh to generate an HTML report.
 lcov:
 	scripts/lcov.sh