Allow multi-word "install" command.

Autoconf can determine that the correct install command includes flags,
e.g., "/usr/bin/install -c". When using this as a command, we can't
enclose the value in double-quotes, as that makes some shells use the
whole expression as a filename:

# this is the value returned by autoconf and stored in CT_install
$ ins="/usr/bin/install -c"

# if we call it with quotes, the command is not found
$ "${ins}"
bash: /usr/bin/install -c: No such file or directory

# removing the quotes lets it work as expected
$ ${ins}
/usr/bin/install: missing file operand
Try `/usr/bin/install --help' for more information.

Signed-Off-By: Anthony Foiani <anthony.foiani@gmail.com>

 diff -ru ltrace-0.5.3.orig/sysdeps/linux-gnu/Makefile ltrace-0.5.3/sysdeps/linux-gnu/Makefile

 --- ltrace-0.5.3.orig/sysdeps/linux-gnu/Makefile	2009-07-25 17:13:02.000000000 +0200

 +++ ltrace-0.5.3/sysdeps/linux-gnu/Makefile	2010-01-01 22:20:45.000000000 +0100

 @@ -2,6 +2,7 @@

  				-e s/i.86/i386/ \

  				-e s/sun4u/sparc64/ \

  				-e s/sparc64/sparc/ \

 +				-e s/alpha.*/alpha/ \

  				-e s/arm.*/arm/ \

  				-e s/sa110/arm/ \

  				-e s/ppc64/ppc/ \