tweaks: use 'void' in prototypes of parameterless functions [coverity]

src/help.c

@@ -40,7 +40,7 @@ static size_t location;
 		/* The offset (in bytes) of the topleft of the shown help text. */
 
 /* Hard-wrap the concatenated help text, and write it into a new buffer. */
-void wrap_help_text_into_buffer()
+void wrap_help_text_into_buffer(void)
 {
 	size_t sum = 0;
 	const char *ptr = start_of_body;

src/nano.c

@@ -243,7 +243,7 @@ void partition_buffer(linestruct *top, size_t top_x,
 }
 
 /* Unpartition the current buffer so that it is complete again. */
-void unpartition_buffer()
+void unpartition_buffer(void)
 {
 	/* Reattach the line that was above the top of the partition. */
 	openfile->filetop->prev = foreline;

src/proto.h

@@ -334,7 +334,7 @@ char *menu_to_name(int menu);
 
 /* All functions in help.c. */
 #ifdef ENABLE_HELP
-void wrap_help_text_into_buffer();
+void wrap_help_text_into_buffer(void);
 void do_help(void);
 void help_init(void);
 functionptrtype parse_help_input(int *kbinput);
@@ -400,7 +400,7 @@ void free_lines(linestruct *src);
 void renumber_from(linestruct *line);
 void partition_buffer(linestruct *top, size_t top_x,
 		linestruct *bot, size_t bot_x);
-void unpartition_buffer();
+void unpartition_buffer(void);
 void extract(linestruct *top, size_t top_x, linestruct *bot, size_t bot_x);
 void ingraft_buffer(linestruct *somebuffer);
 void copy_from_buffer(linestruct *somebuffer);
@@ -469,7 +469,7 @@ int do_yesno_prompt(bool all, const char *msg);
 
 /* Most functions in rcfile.c. */
 #ifdef ENABLE_NANORC
-void display_rcfile_errors();
+void display_rcfile_errors(void);
 #ifdef ENABLE_COLOR
 void parse_one_include(char *file, syntaxtype *syntax);
 void grab_and_store(const char *kind, char *ptr, regexlisttype **storage);

src/rcfile.c

@@ -152,7 +152,7 @@ static linestruct *errors_tail = NULL;
 		/* Beginning and end of a list of errors in rcfiles, if any. */
 
 /* Send the gathered error messages (if any) to the terminal. */
-void display_rcfile_errors()
+void display_rcfile_errors(void)
 {
 	for (linestruct *error = errors_head; error != NULL; error = error->next)
 		fprintf(stderr, "%s\n", error->data);