cmake: fix a path to corpus

Follows up commit 83becb1
("cmake: support C/C++ fuzzing tests by CTest").

NO_CHANGELOG=testing
NO_DOC=testing
NO_TEST=testing

Author: ligurio

test/fuzz/CMakeLists.txt

@@ -88,7 +88,7 @@ function(create_fuzz_test)
   if(EXISTS ${dict_path})
     list(APPEND LIBFUZZER_OPTS_EFFECTIVE "-dict=${dict_path}")
   endif()
-  set(corpus_path ${PROJECT_SOURCE_DIR}/test/static/${FUZZ_PREFIX})
+  set(corpus_path ${PROJECT_SOURCE_DIR}/test/static/corpus/${FUZZ_PREFIX})
   if(EXISTS ${corpus_path})
     list(APPEND LIBFUZZER_OPTS_EFFECTIVE "${corpus_path}")
   endif()