Don't hardcode /usr, use @prefix@.

Author: Bjørn Forsman
diff -uNr espeakedit-1.48.03.orig/src/speech.h espeakedit-1.48.03/src/speech.h
--- espeakedit-1.48.03.orig/src/speech.h	2014-03-04 17:48:12.000000000 +0100
+++ espeakedit-1.48.03/src/speech.h	2014-07-22 18:21:40.860790719 +0200
@@ -58,7 +58,7 @@
 
 // will look for espeak_data directory here, and also in user's home directory
 #ifndef PATH_ESPEAK_DATA
-   #define PATH_ESPEAK_DATA  "/usr/share/espeak-data"
+   #define PATH_ESPEAK_DATA  "@prefix@/share/espeak-data"
 #endif
 
 typedef unsigned short USHORT;