perf build: Rename LIB_PATH -> API_PATH

'LIB_PATH' is a misnomer because there are multiple library paths.

Signed-off-by: Josh Poimboeuf <[e-mail]>
Acked-by: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Makefile.perf

···
   TE_PATH=$(OUTPUT)
   BPF_PATH=$(OUTPUT)
 ifneq ($(subdir),)
-  LIB_PATH=$(OUTPUT)/../lib/api/
+  API_PATH=$(OUTPUT)/../lib/api/
 else
-  LIB_PATH=$(OUTPUT)
+  API_PATH=$(OUTPUT)
 endif
 else
   TE_PATH=$(TRACE_EVENT_DIR)
-  LIB_PATH=$(LIB_DIR)
+  API_PATH=$(LIB_DIR)
   BPF_PATH=$(BPF_DIR)
 endif
 
···
 LIBTRACEEVENT_DYNAMIC_LIST = $(TE_PATH)libtraceevent-dynamic-list
 LIBTRACEEVENT_DYNAMIC_LIST_LDFLAGS = -Xlinker --dynamic-list=$(LIBTRACEEVENT_DYNAMIC_LIST)
 
-LIBAPI = $(LIB_PATH)libapi.a
+LIBAPI = $(API_PATH)libapi.a
 export LIBAPI
 
 LIBBPF = $(BPF_PATH)libbpf.a