perf tools: Disable JVMTI if no ELF support available

The build of JVMTI depends on LIBELF (-lelf). Make Makefile.conf
check this dependendancy and notify user when not present.

v2: Comma nitpicking.

Signed-off-by: David Carrillo-Cisneros <[e-mail]>
Tested-by: Kim Phillips <[e-mail]>
Acked-by: Jiri Olsa <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Cc: He Kuang <[e-mail]>
Cc: Masami Hiramatsu <[e-mail]>
Cc: Paul Turner <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Simon Que <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Cc: Wang Nan <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Makefile.config

···
   NO_LIBUNWIND := 1
   NO_LIBDW_DWARF_UNWIND := 1
   NO_LIBBPF := 1
+  NO_JVMTI := 1
 else
   ifeq ($(feature-libelf), 0)
     ifeq ($(feature-glibc), 1)
···
       LIBC_SUPPORT := 1
     endif
     ifeq ($(LIBC_SUPPORT),1)
-      msg := $(warning No libelf found, disables 'probe' tool and BPF support in 'perf record', please install libelf-dev, libelf-devel or elfutils-libelf-devel);
+      msg := $(warning No libelf found. Disables 'probe' tool, jvmti and BPF support in 'perf record'. Please install libelf-dev, libelf-devel or elfutils-libelf-devel);
 
       NO_LIBELF := 1
       NO_DWARF := 1
···
       NO_LIBUNWIND := 1
       NO_LIBDW_DWARF_UNWIND := 1
       NO_LIBBPF := 1
+      NO_JVMTI := 1
     else
       ifneq ($(filter s% -static%,$(LDFLAGS),),)
         msg := $(error No static glibc found, please install glibc-static);