riscv: kselftests: Fix mm build by removing testcases subdirectory

kselftests fails to build because the mm/testcases subdirectory is not
created and then the compiler fails to output the binary there.

So fix this by simply removing this subdirectory which is not very
useful.

Signed-off-by: Alexandre Ghiti <[e-mail]>
Reviewed-by: Charlie Jenkins <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Palmer Dabbelt <[e-mail]>

tools/testing/selftests/riscv/mm/Makefile

···
 # Additional include paths needed by kselftest.h and local headers
 CFLAGS += -D_GNU_SOURCE -std=gnu99 -I.
 
-TEST_GEN_FILES := testcases/mmap_default testcases/mmap_bottomup
+TEST_GEN_FILES := mmap_default mmap_bottomup
 
-TEST_PROGS := testcases/run_mmap.sh
+TEST_PROGS := run_mmap.sh
 
 include ../../lib.mk
 
-$(OUTPUT)/mm: testcases/mmap_default.c testcases/mmap_bottomup.c testcases/mmap_tests.h
+$(OUTPUT)/mm: mmap_default.c mmap_bottomup.c mmap_tests.h
 	$(CC) -o$@ $(CFLAGS) $(LDFLAGS) $^

tools/testing/selftests/riscv/mm/testcases/mmap_bottomup.c tools/testing/selftests/riscv/mm/mmap_bottomup.c

···
 // SPDX-License-Identifier: GPL-2.0-only
 #include <sys/mman.h>
-#include <testcases/mmap_test.h>
+#include <mmap_test.h>
 
 #include "../../kselftest_harness.h"
 

tools/testing/selftests/riscv/mm/testcases/mmap_default.c tools/testing/selftests/riscv/mm/mmap_default.c

···
 // SPDX-License-Identifier: GPL-2.0-only
 #include <sys/mman.h>
-#include <testcases/mmap_test.h>
+#include <mmap_test.h>
 
 #include "../../kselftest_harness.h"