Fix naming of library on PPC64LE (#6080)

Summary:
**NOTE**: This also needs to be back-ported to be 6.4.6

Fix a regression introduced in f2bf0b2 by https://github.com/facebook/rocksdb/pull/5674 whereby the compiled library would get the wrong name on PPC64LE platforms.

On PPC64LE, the regression caused the library to be named `librocksdbjni-linux64.so` instead of `librocksdbjni-linux-ppc64le.so`.

This PR corrects the name back to `librocksdbjni-linux-ppc64le.so` and also corrects the ordering of conditional arguments in the Makefile to match the expected order as defined in the documentation for Make.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6080

Differential Revision: D18710351

fbshipit-source-id: d4db87ef378263b57de7f9edce1b7d15644cf9de

Makefile

@@ -1722,7 +1722,7 @@ JAVA_INCLUDE = -I$(JAVA_HOME)/include/ -I$(JAVA_HOME)/include/linux
 ifeq ($(PLATFORM), OS_SOLARIS)
 	ARCH := $(shell isainfo -b)
 else ifeq ($(PLATFORM), OS_OPENBSD)
-	ifneq (,$(filter $(MACHINE), amd64 arm64 aarch64 sparc64))
+	ifneq (,$(filter amd64 ppc64 ppc64le arm64 aarch64 sparc64, $(MACHINE)))
 		ARCH := 64
 	else
 		ARCH := 32
@@ -1731,10 +1731,10 @@ else
 	ARCH := $(shell getconf LONG_BIT)
 endif
 
-ifeq (,$(filter $(MACHINE), ppc arm64 aarch64 sparc64))
-        ROCKSDBJNILIB = librocksdbjni-linux$(ARCH).so
-else
+ifneq (,$(filter ppc% arm64 aarch64 sparc64, $(MACHINE)))
 	ROCKSDBJNILIB = librocksdbjni-linux-$(MACHINE).so
+else
+	ROCKSDBJNILIB = librocksdbjni-linux$(ARCH).so
 endif
 ROCKSDB_JAR = rocksdbjni-$(ROCKSDB_MAJOR).$(ROCKSDB_MINOR).$(ROCKSDB_PATCH)-linux$(ARCH).jar
 ROCKSDB_JAR_ALL = rocksdbjni-$(ROCKSDB_MAJOR).$(ROCKSDB_MINOR).$(ROCKSDB_PATCH).jar