hal/hisi: fix strcpy-param-overlap in get_hisi_sdk (UB, caught by ASAN) (#173)

get_hisi_sdk() reformats the /proc/umap/sys version line into
"<version> (<build time>)". line_from_file() returns the *greedy* capture
of `Version: \[(.+)\]`, so on a typical Hisilicon line such as

  [SYS] Version: [Hi3516CV500_MPP_V2.0.2.1 B030 Release], Build Time[May 28 2020, 11:04:35]

buf ends up spanning BOTH brackets. The code overwrites the first ']' with
" (" and then splices the build time in via strcpy(ptr, build + 1) -- but
build+1 and ptr alias the same buffer, so that is an overlapping copy.
strcpy() with overlapping ranges is undefined behaviour; it only happens to
produce the right string on glibc because the copy direction reads before it
writes. AddressSanitizer aborts on it (strcpy-param-overlap), and a different
libc/arch could silently corrupt the string.

Use memmove(), which is well-defined for overlap and yields the identical
"<version> (<build time>)" result.

Found by running an ASAN-instrumented build on a live Hi3516CV500 (glibc)
camera; after the fix the full run completes ASAN-clean with
sdk: "Hi3516CV500_MPP_V2.0.2.1 B030 Release (May 28 2020, 11:04:35)".

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: widgetii

src/hal/hisi/hal_hisi.c

@@ -474,7 +474,12 @@ static void get_hisi_sdk(cJSON *j_inner) {
             return;
         *ptr++ = ' ';
         *ptr++ = '(';
-        strcpy(ptr, build + 1);
+        /* build+1 and ptr alias the same buffer (the bracketed build
+         * time sits after the ']' we just overwrote), so this is an
+         * overlapping copy: strcpy() is UB here (ASAN: strcpy-param-
+         * overlap), memmove() is well-defined and yields the same
+         * "<version> (<build time>)" string. */
+        memmove(ptr, build + 1, strlen(build + 1) + 1);
         strcat(ptr, ")");
         ADD_PARAM("sdk", buf);
     }