autotools: Add LD_LIBRARY_PATH instructions to the README

Signed-off-by: Ken Goldman <[email protected]>

README

@@ -28,10 +28,17 @@ Refer to the "Advanced options", below, for additional compiler options.
 Autotools
 ---------
 
-On Linux (and probably other Unix systems), open source projects expect
+On Linux (and probably other Unix systems), open source projects expect that
 the normal shell command 'autoreconf -i && ./configure && make && make install'
 should configure and build the package.
 
+If --prefix is omitted, the default /usr/local is used.  
+
+The LD_LIBRARY_PATH environment variable must be set to the path
+(either the default or a user specified path).  E.g.,
+
+export LD_LIBRARY_PATH=/usr/local/lib
+
 Example 1: To configure the TSS library to use the software TPM, build and
 install the package in ${HOME}/local/bin and ${HOME}/local/lib directories
 execute the following shell commands: