Realtek Hd Audio Drivers Can't Be Installed

I am receiving the following error on make install as suggested in the Realtek Audio driver package. I installed the driver from this website.

The error I am getting is:

/bin/sh: 1: Syntax error: "(" unexpected
/bin/sh: 1: Syntax error: "(" unexpected
/bin/sh: 1: Syntax error: "(" unexpected
/bin/sh: 1: Syntax error: "(" unexpected
/bin/sh: 1: Syntax error: "(" unexpected
/bin/sh: 1: Syntax error: "(" unexpected
if [ -L /usr/include/sound ]; then \
  rm -f /usr/include/sound; \
 ln -sf /home/sachin/Downloads/Rt-Linux-HDaudio-5.18 (2)/alsa-driver-RTv5.18/alsa/include/sound /usr/include/sound; \   
 else \
rm -rf /usr/include/sound; \
install -d -m 755 -g root -o root /usr/include/sound; \
for f in include/sound/*.h; do \
    install -m 644 -g root -o root $f /usr/include/sound; \
done \
fi
/bin/sh: 3: Syntax error: "(" unexpected (expecting "fi")
Makefile:188: recipe for target 'install-headers' failed
make: *** [install-headers] Error 2

Please help me resolve it. Thank you.