Check -U option for unknown memories during parsing

$ avrdude -qp ATmega2560 -c usbtiny -U flesh:w:blink-mega2560+lext-test.hex:i
avrdude: unknown memory type flesh
avrdude: error parsing update operation 'flesh:w:blink-mega2560+lext-test.hex:i'

src/avr.c

@@ -1253,7 +1253,7 @@ void avr_add_mem_order(const char *str) {
   exit(1);
 }
 
-int avr_known_mem(const char *str) {
+int avr_mem_is_known(const char *str) {
   for(size_t i=0; i < sizeof avr_mem_order/sizeof *avr_mem_order; i++)
     if(avr_mem_order[i] && !strcmp(avr_mem_order[i], str))
       return 1;

src/libavrdude.h

@@ -821,7 +821,7 @@ int avr_put_cycle_count(PROGRAMMER * pgm, AVRPART * p, int cycles);
 
 void avr_add_mem_order(const char *str);
 
-int avr_known_mem(const char *str);
+int avr_mem_is_known(const char *str);
 
 #define disable_trailing_ff_removal() avr_mem_hiaddr(NULL)
 int avr_mem_hiaddr(AVRMEM * mem);

src/update.c

@@ -62,6 +62,12 @@ UPDATE * parse_op(char * s)
     return upd;
   }
 
+  if (!avr_mem_is_known(buf)) {
+    avrdude_message(MSG_INFO, "%s: unknown memory type %s\n", progname, buf);
+    free(upd);
+    return NULL;
+  }
+
   upd->memtype = (char *)malloc(strlen(buf)+1);
   if (upd->memtype == NULL) {
     avrdude_message(MSG_INFO, "%s: out of memory\n", progname);