remove unused JAMVM_DIR_PREFIX

package/java/jamvm/jamvm.mk

@@ -11,7 +11,6 @@ JAMVM_INSTALL_STAGING = YES
 JAMVM_INSTALL_TARGET = YES
 JAMVM_INSTALL_STAGING_OPT = DESTDIR=$(STAGING_DIR) install
 JAMVM_INSTALL_TARGET_OPT = DESTDIR=$(TARGET_DIR) install
-JAMVM_DIR_PREFIX = package/java
 
 JAMVM_CONF_ENV = ac_cv_func_posix_getpwuid_r=yes glib_cv_stack_grows=no \
 		glib_cv_uscore=no ac_cv_func_strtod=yes \