examples/fxload: Eliminate all reserved C identifiers (leading underscores)

The C langugage reserves various identifiers for itself that user code
must not use.

Fixes all clang-tidy bugprone-reserved-identifier warnings

Also, 4 of 5 file extension tests were case insensitive, and 1 was not.
Changed it to be insensitive too.

References #1479

.clang-tidy

@@ -9,7 +9,6 @@ bugprone-*,\
 -bugprone-macro-parentheses,\
 -bugprone-misplaced-widening-cast,\
 -bugprone-narrowing-conversions,\
--bugprone-reserved-identifier,\
 -bugprone-signed-char-misuse,\
 -bugprone-suspicious-string-compare,\
 -bugprone-switch-missing-default-case,\

examples/fxload.c

@@ -38,7 +38,9 @@
 #include <syslog.h>
 static bool dosyslog = false;
 #include <strings.h>
-#define _stricmp strcasecmp
+#define libusb_strcasecmp strcasecmp
+#else
+#define libusb_strcasecmp _stricmp
 #endif
 
 #ifndef FXLOAD_VERSION
@@ -263,13 +265,13 @@ int main(int argc, char*argv[])
 	for (i=0; i<ARRAYSIZE(path); i++) {
 		if (path[i] != NULL) {
 			ext = path[i] + strlen(path[i]) - 4;
-			if ((_stricmp(ext, ".hex") == 0) || (strcmp(ext, ".ihx") == 0))
+			if ((libusb_strcasecmp(ext, ".hex") == 0) || (libusb_strcasecmp(ext, ".ihx") == 0))
 				img_type[i] = IMG_TYPE_HEX;
-			else if (_stricmp(ext, ".iic") == 0)
+			else if (libusb_strcasecmp(ext, ".iic") == 0)
 				img_type[i] = IMG_TYPE_IIC;
-			else if (_stricmp(ext, ".bix") == 0)
+			else if (libusb_strcasecmp(ext, ".bix") == 0)
 				img_type[i] = IMG_TYPE_BIX;
-			else if (_stricmp(ext, ".img") == 0)
+			else if (libusb_strcasecmp(ext, ".img") == 0)
 				img_type[i] = IMG_TYPE_IMG;
 			else {
 				logerror("%s is not a recognized image type\n", path[i]);

libusb/version_nano.h

@@ -1 +1 @@
-#define LIBUSB_NANO 11914
+#define LIBUSB_NANO 11915