fix coverity scan errors

Author: luo-cheng2021

src/common/tensor2d.hpp

@@ -23,7 +23,7 @@ struct tensor2D {
     int64_t capacity = 0;
     int stride = 0;
     bool force_compact = false;
-    bool own;
+    bool own = false;
     int padded_dim1 = 0;
 
     tensor2D() = default;

src/mm_kernel_common_amx.hpp

@@ -459,6 +459,9 @@ namespace functional {
                 re = _mm512_setzero_epi32();
                 rf = _mm512_setzero_epi32();
                 break;
+            default:
+                assert(false);
+                return;
         }
 
         transpose_m512i_16x16(r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, ra, rb, rc, rd, re, rf);
@@ -802,6 +805,9 @@ namespace functional {
                 re = _mm512_setzero_epi32();
                 rf = _mm512_setzero_epi32();
                 break;
+            default:
+                assert(false);
+                return;
         }
         transpose_m512i_16x16(r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, ra, rb, rc, rd, re, rf);
         _mm512_storeu_epi32(dst, r0);