HADOOP-17508. Simplify deps install instructions (#2664)

(cherry picked from commit a163aa739482d05a2e82f84d7b4f9b562ed1ab99)

 Conflicts:
	BUILDING.txt

BUILDING.txt

@@ -63,15 +63,12 @@ Installing required packages for clean install of Ubuntu 14.04 LTS Desktop:
 * Native libraries
   $ sudo apt-get -y install build-essential autoconf automake libtool cmake zlib1g-dev pkg-config libssl-dev libsasl2-dev
 * Protocol Buffers 3.7.1 (required to build native code)
-  $ mkdir -p /opt/protobuf-3.7-src \
-        && curl -L -s -S \
-          https://github.com/protocolbuffers/protobuf/releases/download/v3.7.1/protobuf-java-3.7.1.tar.gz \
-          -o /opt/protobuf-3.7.1.tar.gz \
-        && tar xzf /opt/protobuf-3.7.1.tar.gz --strip-components 1 -C /opt/protobuf-3.7-src \
-        && cd /opt/protobuf-3.7-src \
-        && ./configure\
-        && make install \
-        && rm -rf /opt/protobuf-3.7-src
+  $ curl -L -s -S https://github.com/protocolbuffers/protobuf/releases/download/v3.7.1/protobuf-java-3.7.1.tar.gz -o protobuf-3.7.1.tar.gz
+  $ mkdir protobuf-3.7-src
+  $ tar xzf protobuf-3.7.1.tar.gz --strip-components 1 -C protobuf-3.7-src && cd protobuf-3.7-src
+  $ ./configure
+  $ make -j$(nproc)
+  $ sudo make install
 
 Optional packages: