[HALARM] Bound early debug print formatting (#9017)

Replace unbounded vsprintf() call in DbgPrintEarly() with vsnprintf()
when formatting into a fixed-size 1024-byte stack buffer in ARM HAL.

Automated security fix generated by Orbis Security AI.

CORE-17604

Co-authored-by: OrbisAI Security <[email protected]>

hal/halarm/generic/halinit.c

@@ -165,7 +165,7 @@ DbgPrintEarly(const char *fmt, ...)
     PCHAR String = Buffer;
 
     va_start(args, fmt);
-    i = vsprintf(Buffer, fmt, args);
+    i = vsnprintf(Buffer, sizeof(Buffer), fmt, args);
     va_end(args);
 
     /* Output the message */