perf annotate: Fix a comment about multi_regs in extract_reg_offset function

Fix a comment in function which explains how multi_regs field gets set
for an instruction. In the example, "mov  %rsi, 8(%rbx,%rcx,4)", the
comment mistakenly referred to "dst_multi_regs = 0". Correct it to use
"src_multi_regs = 0"

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Akanksha J N <akanksha@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Link: https://lore.kernel.org/r/20240506121906.76639-4-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Author: athira-rajeev

tools/perf/util/annotate.c

@@ -2092,7 +2092,7 @@ static int extract_reg_offset(struct arch *arch, const char *str,
  *   mov  0x18, %r8      # src_reg1 = -1, src_mem = 0
  *                       # dst_reg1 = r8, dst_mem = 0
  *
- *   mov  %rsi, 8(%rbx,%rcx,4)  # src_reg1 = rsi, src_mem = 0, dst_multi_regs = 0
+ *   mov  %rsi, 8(%rbx,%rcx,4)  # src_reg1 = rsi, src_mem = 0, src_multi_regs = 0
  *                              # dst_reg1 = rbx, dst_reg2 = rcx, dst_mem = 1
  *                              # dst_multi_regs = 1, dst_offset = 8
  */