fix: invalid offset error, clobbering error

fixed errors:

./blamka_amd64.s:203:1: [amd64] mixBlocksSSE2: invalid offset a+24(FP); expected a+8(FP)

./blamka_amd64.s:226:1: [amd64] xorBlocksSSE2: invalid offset a+24(FP); expected a+8(FP)

./blamka_amd64.s:204:1: frame pointer is clobbered before saving

./blamka_amd64.s:227:1: frame pointer is clobbered before saving

blamka_amd64.s

@@ -197,10 +197,12 @@ TEXT ·blamkaSSE4(SB), 4, $0-8
 
 // func mixBlocksSSE2(out, a, b, c *block)
 TEXT ·mixBlocksSSE2(SB), 4, $0-32
+	// Save the original BP value
+	MOVQ BP, CX
 	MOVQ out+0(FP), DX
 	MOVQ a+8(FP), AX
 	MOVQ b+16(FP), BX
-	MOVQ a+24(FP), CX
+	MOVQ c+24(FP), CX
 	MOVQ $128, BP
 
 loop:
@@ -216,14 +218,18 @@ loop:
 	ADDQ  $16, DX
 	SUBQ  $2, BP
 	JA    loop
+	// Restore the original BP value
+	MOVQ CX, BP
 	RET
 
 // func xorBlocksSSE2(out, a, b, c *block)
 TEXT ·xorBlocksSSE2(SB), 4, $0-32
+	// Save the original BP value
+	MOVQ BP, CX
 	MOVQ out+0(FP), DX
 	MOVQ a+8(FP), AX
 	MOVQ b+16(FP), BX
-	MOVQ a+24(FP), CX
+	MOVQ c+24(FP), CX
 	MOVQ $128, BP
 
 loop:
@@ -241,4 +247,6 @@ loop:
 	ADDQ  $16, DX
 	SUBQ  $2, BP
 	JA    loop
-	RET
+	// Restore the original BP value
+	MOVQ CX, BP
+	RET