Makefile fix for when there are two occurrences of jni_md.h (reported/fixed by Gaston Ingaramo).

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@7521 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/Makefile

@@ -262,7 +262,7 @@ JAVA_JNI_H_DIR = $(shell \
 	if [ -f "$(JAVA_DIR)"/include/jni.h ]; then echo "$(JAVA_DIR)"/include; \
 	elif [ -f "$(JAVA_DIR)"/Headers/jni.h ]; then echo "$(JAVA_DIR)"/Headers; \
 	else echo ""; fi )
-JAVA_JNI_MD_H_DIR = $(shell (ls "$(JAVA_JNI_H_DIR)"/jni_md.h "$(JAVA_JNI_H_DIR)"/*/jni_md.h | sed 's/\/jni_md.h//') 2>/dev/null)
+JAVA_JNI_MD_H_DIR = $(shell (ls "$(JAVA_JNI_H_DIR)"/jni_md.h "$(JAVA_JNI_H_DIR)"/*/jni_md.h | head -n 1 | sed 's/\/jni_md.h//') 2>/dev/null)
 JAVA_INCLUDES = -I $(JAVA_JNI_H_DIR) -I $(JAVA_JNI_MD_H_DIR)
 
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