Remove redundant extern storage class specifier in functions

dselect/method.h

@@ -89,8 +89,8 @@ extern int noptions;
 extern struct dselect_option *options, *coption;
 extern struct method *methods;
 
-extern void readmethods(const char *pathbase, dselect_option **optionspp, int *nread);
-extern void getcurrentopt();
-extern void writecurrentopt();
+void readmethods(const char *pathbase, dselect_option **optionspp, int *nread);
+void getcurrentopt();
+void writecurrentopt();
 
 #endif /* METHOD_H */

lib/dpkg/dpkg-db.h

@@ -445,7 +445,7 @@ int epochsdiffer(const struct versionrevision *a,
                  const struct versionrevision *b);
 
 /*** from nfmalloc.c ***/
-extern void *nfmalloc(size_t);
+void *nfmalloc(size_t);
 char *nfstrsave(const char*);
 char *nfstrnsave(const char*, size_t);
 void nffreeall(void);

lib/dpkg/tarfn.h

@@ -62,6 +62,6 @@ struct TarFunctions {
 };
 typedef struct TarFunctions	TarFunctions;
 
-extern int	TarExtractor(void * userData, const TarFunctions * functions);
+int TarExtractor(void *userData, const TarFunctions *functions);
 
 #endif